seismic analysis of the minaret

CONTENTS

Magribija mosque's minaret 1 / 17

CONTENTS:

Chapter – 1 ABSTRACT

1.1. MASONRY MINARET OF MAGRIBIJA MOSQUE ........................................................................................................................................ 2

1.2. SEISMIC BEHAVIOR OF HISTORIC MASONRY MINARET ........................................................................................................................ 2

Chapter – 2 MAGRIBIJA MOSQUE

2.1. LOCATION .................................................................................................................................................................................................. 3

2.2. HISTORICAL INFORMATIONS ................................................................................................................................................................... 4

2.3. DESCRIPTION OF THE MOSQUE .............................................................................................................................................................. 5 2.3.1. The mosque .................................................................................................................................................................................................................... 5 2.3.2. The stone minaret ........................................................................................................................................................................................................... 7 2.3.3. The main prayer space ................................................................................................................................................................................................... 7 2.3.4. The entrance portal ......................................................................................................................................................................................................... 8 2.3.5. The mahfil ....................................................................................................................................................................................................................... 8 2.3.6. The mihrab ...................................................................................................................................................................................................................... 8 2.3.7. The minber ...................................................................................................................................................................................................................... 9 2.3.8. The ćurs .......................................................................................................................................................................................................................... 9

2.4. LEGAL STATUS TO DATE ........................................................................................................................................................................ 10

2.5. RESEARCH AND CONSERVATION AND RESTORATION WORKS ......................................................................................................... 10

2.6. CURRENT CONDITION OF THE MOSQUE ............................................................................................................................................... 12

Chapter – 3 STRUCTURAL ANALYSIS

3.1. GEOMETRICAL AND MATERIAL PROPERTIES OF THE MINARET ........................................................................................................ 13

3.2. NUMERICAL 3D MODEL ........................................................................................................................................................................... 14 3.2.1. Modal Analysis .............................................................................................................................................................................................................. 14 3.2.2. Seismic Analysis ........................................................................................................................................................................................................... 15

Chapter – 4 CONCLUSION

1 Abstract


1.1. MASONRY MINARET OF MAGRIBIJA MOSQUE

The mid-16th century Sheikh Magribija Mosque at the heart of Sarajevo is one of the most important Ottoman monuments in the city. During

the war in Bosnia and Herzegovina an artillery shell destroyed the minaret and other key elements.

Year 2000, UNESCO-Sarajevo, in association with the Cantonal Institute, attracted $32,300 of a total budget $47,100 from the High Saudi Committee for Relief in Bosnia and Herzegovina.

Restoration endorsed by donor and observers and the mosque has returned to active community use, although its urban surroundings are

in poor condition. The casual visitor would not recognize the building’s significance – but this could be an endorsement of its success as restored.

1.2. SEISMIC BEHAVIOR OF HISTORIC MASONRY MINARET

The dynamic behavior of block masonry minaret of a historical mosque in Sarajevo is analyzed, and a seismic retrofit method is proposed.

Due to high seismicity of the region, a 3D finite element model is used to determine lateral displacements and failure modes under seismic load.

The analyses show that the highest damage usually occurs at the base and the lower part of the minaret, and that lateral behaviour can be

improved by strengthening these sections with fiber reinforced polymer (FRP) sheets. The results obtained are promising in terms of seismic

protection. This work aims to determine stability of Magribija mosque’s minaret during the earthquakes and determine itself capacity on horizontal

loadings.

KEY WORDS: stone masonry minaret, earthquake, fiber reinforced polymer

2 MAGRIBIJA MOSQUE


Fig. 1-1: Location of Magribija mosque, Sarajevo, BiH

2.1. LOCATION

The Magribija mosque is located at n. 5 Magribija street, close to Marindvor in Sarajevo, Bosnia and Herzegovina, which at the time the

mosque was built constituted the western outskirts of old Sarajevo. It is now part of the city belonging to Centar Sarajevo Municipality.

The building stands on c.p. no.

832 (new survey), or c.p. nos. 1 and 82

(old survey), and is owned by the Islamic

Religious Community in Sarajevo. The

mosque is right by Magribija street, and

has no harem (courtyard) but merely a

fenced-off green space to the west of the

building. The plot on which it stands is

relatively small: the mosque occupies an

area of 158 m2 and the mosque courtyard

223 m2. The entrance is to the north-

west, from Magribija street.

The buildings standing on

neighboring plots c.p. 829 and 830 are

very close to the Magribija mosque,

particularly the Sarajevostan building

which is only about 4-5 meters from the

south-east facade of the mosque.

- Zmaja od Bosne - - Hiseta -

Magribija Mosque

Chapter – 2 Magribija Mosque


2.2. HISTORICAL INFORMATIONS

Sheikh Magribija’s mosque, known

as the Magribija, was erected in Sarajevo

close to Marindvor, in a quarter formerly

known as Zagorica, the quarter below

Gorica.

Local tradition holds that Sheikh

Magribija came to Sarajevo with Isa-beg

(founder of the city and first governor of

Sarajevo) and that he built a mosque there.

Almost nothing is known of Sheikh

Magribija except that his name suggests he

was a member of a Sufi order and that he

came from the Maghreb, the term used to

denote the Islamic lands of North Africa:

Tunis, Algeria and Morocco. If this tradition

is correct the mosque dated from the mid-

16th century and was named after its

founder. Later the name Magribija was

used for the mahala too and the street

which has now borne the name for 400

years. The quarter too was known as

Magribija, after the mosque. In the late

Ottoman period the mahala was also known

Gornja Hiseta.

H. Šabanović regards the dating of

the Magribija mosque as an open question,

which leaves the possibility that the original

mosque was indeed built during the time of

the founder of Sarajevo but that it burned

down in the fire of 1459.

According to Šabanović, the

Magribija mosque in its present form could

date from between 1538 and 1565, when it

is first mentioned in a document from the

Sarajevo sidžil (court records). It was

burned down again in 1697 during the

campaign by Eugene of Savoy, when all

that survived were the walls and the stone

minaret.

According to an account by Mula

Mustafa Bašeskija, the mosque was rebuilt

in 1766 with the help of the state, and the

present appearance of the mosque and all

the painted decorations date from that year.

The famous English scholar Sir

Thomas W. Arnold visited Sarajevo in 1929

and was particularly impressed by the

Magribija mosque. He was interested in the

wooden pillars with stone bases and

capitals on the sofas, the structure of the

šiše ceiling and the beautiful painted

decorations on the woodwork inside the

mosque. He noted that he had seen

something similar in mosques in Delhi, in

India, but nowhere else in the world (from

an article in the Evening Post).

According to information from the

Cantonal Institute for the Protection of the

Cultural, Historical and Natural Heritage of

Sarajevo, between 1971 and 1984 research

and conservations works were carried out

on the painted decorations of the Magribija

mosque.

The Magribija mosque was

damaged during the war by shelling in

August 1992. The minaret was knocked

down to pedestal level, and the roof

suffered major damage, as did the entire

building.



Fig. 2-1: View on entrance of Magribija mosque

Fig. 2-2: Side view of the mosque

2.3. DESCRIPTION OF THE MOSQUE

2.3.1. The mosque

Bosnia and Herzegovina has many more mosques with hipped

roofs and stone minarets than domed mosques. According to statistics

dating from 1993, there were 223 of them. Sarajevo had the most,

mosques with stone minarets, 34 before the war and 26 now. In ground

plan the Magribija mosque belongs to the type of single-space mosque

with a hipped roof and stone minaret.

The mosque consists of the main prayer space and a portico on the north-

west entrance front of the mosque extending over the entire width of the

exterior wall, and a stone minaret. The main prayer space and portico

share the same hipped roof. The ground plan of the mosque is a

rectangle, measuring 13.80 x 11.30 (exterior dimensions), with the portico

measuring 18.15 x 11.30 m. Within the portico are stone sofas measuring

approx. 4.53 x 4.35 m, with a height of 0.50 m. The sofas have wooden

floorboards. The 2.25 m wide passageway to the mosque portal passed

between the sofas.

There are four massive wooden columns with a height of 3.75 m and a diameter of approx.

0.50 m. The columns have stone bases and capitals with decorative moldings. Between the wooden

columns is a wooden railing above a stone wall about 2.00 m high, thought somewhat lower at the

sides. The entrance door, with a height of approx. 2.00 m., is of wide wooden boards set one against

the other. The upper part of the portico consists of a wooden structure with arches, six on the entrance

front and three each on the sides, resting on a wooden 20 x 20 cm beam which itself rests on the

capitals of the pillars. The roof structure of the portico is covered with wood paneling.



Fig. 2-4: South-west faced – wooden windows

Fig. 2-3: Wooden columns with capitals

The walls of the main body of the mosque are of unfired brick

with wooden tie beams, plastered and painted both inside and out.

The walls are 80 cm thick. The hipped roof is shallow pitched, with a

wooden roof structure clad with tiles. There are dormer windows on

all four sides of the roof, serving as exits to and ventilation for the

roof. They measure approx. 1.50 x 1.0 m.

The mosque has seventeen simply-shaped wooden windows,

six on the south-west facade, three on the north-east, and four each

on the north-west and the south-east facades. The windows are set in

two rows, except in the north-east facade where there are windows

on the upper level only. There was formerly a row of windows at

ground floor level too, but they have been walled up and are now

visible as niches in the interior of the mosque, used as bookshelves.

All the ground-floor windows are rectangular in shape, 92 cm wide

and 150 cm high. Above each of the ground-floor windows is a small

wooden arched, glazed aperture, almost the same width as the

window itself, with the pointed arch 70 cm in height. On the outside,

these windows have iron bars forming a fine grid (4 x 5 sections).

The upper-level windows are arched and set vertically above the

ground-floor windows. They too are 92 cm in width, but 200 cm in

height.

In addition to these windows, there are another five glazed

circular apertures in wooden frames on all the facades except the

entrance facade. These have a diameter of 55 cm. There are two on

each of the side facades and one on the mihrab facade, between and

level with the top line of the upper-level windows.



Fig. 2-5: The stone minaret

Fig. 2-6: The main prayer space

2.3.2. The stone minaret

The stone minaret of the Magribija mosque was built against the south-west facade

wall. The base of the minaret is in the form of a square-sided cube measuring 2.26 x 2.26

m. The transition from the four-sided base to the stem of the minaret is in the form of a

trapezoid prism with a shallow molded stone string course. The twelve-sided body of the

minaret is slightly conical in shape, with a diameter of approx. 1.85 m. and walls 26-30 cm

thick. The šerefe is at a height of 14.50 m. and is of hreša stone. The parapet of the šerefe

is of simple stone slabs with pronounced upper and lower molded string courses. The

steeple of the minaret is clad with sheet copper and topped by an alem or finial made of

lead, with four equal-sized pommels. The total height of the minaret from ground level is

32.0 m.

2.3.3. The main prayer space

The portico leads into the main prayer space, with interior dimensions of 12.20 x

9.70 m. The prayer area is covered by a timber barrel vault running longitudinally along the

north-west/south-east axis. This vault measures approx. 5.0 x 7.5 m. The height of the

prayer space from floor level to the top of the barrel vault is approx. 7.9 m. The vault turns

into a level ceiling on all four sides; this ceiling is 6.4 m above floor level and is clad with šiše

boards (grooved wooden boards). The barrel

section is clad with caisson boards painted

with polychrome motifs, mainly of floral origin,

with a circular rosette filled with floral

ornaments at the center. All the interior walls

of the mosque are plastered and whitewashed,

and some areas and features have painted

decorations.



Fig. 2-7: The mihrab

2.3.4. The entrance portal

The entrance portal dominates the central area of the north-west facade, occupying in width the entire space between the sofas. It is

approx. 5.90 m in height and projects outwards from the surface of the mosque walls by approx. 0.25 m. Above the arched door opening is a niche

in the form of an equilateral triangle. In the niche above the door is the place where the tarih (chronogram) used to be, measuring 75 x 40 cm. The

portal terminates in a crown in the form of a stylized fleur de lis.

The entire portal was thickly painted with polychrome floral decorations on plaster, which are now barely visible. The double wooden doors

are 1.4 m wide and 2.20 m. high. They are divided into rectangular panels without any particular decoration.

2.3.5. The mahfil

The mahfil runs along the front wall and measures 9,70 m long and 2.30 wide. It is made of wood and rests on six wooden pillars linked by

wooden arches below the mahfil. The wooden pillars are decorated with wood carving and the entire surface of the arches is painted in floral

designs composed of flowers, leaves and tendrils. The painted decoration consists of dark-toned outlines

surrounding light red, grey and beige.

Below the mahfil are interior sofas measuring 3.70 x 2.00 m, with raised floors. The area of the

sofa and the part of the mahfil against the north-east wall are now glazed. At the center of the mahfil is a

1.00 m wide projection for the muezzin. The mahfil is paneled above and below with wooden boards and

has a wooden railing. The small door leading to the narrow, dark, curving minaret stairway is located below

the mahfil in the south-west wall of the mosque. The mahfil is reached via the stone minaret stairway, with

a single-flight wooden staircase approximately halfway along branching off it to the mahfil. The wooden

structure of the mahfil is of natural wood treated with wood preservative.

2.3.6. The mihrab

The mihrab is 2.55 m wide, with the niche itself 1.55 m wide and the frame 70 cm wide on either

side. The height of the mihrab from the floor of the mosque to the top of the crown of the mihrab is approx.

3.50 m. The seven-sided niche, with a radius of 40 cm, terminates in stalactite decorations forming a

complex composition. The niche area is framed by the rectangular field of the mihrab frame, which

terminates in a wavy semicircular line with a fleur de lis at the top and demi fleur de lis at the sides. The



Fig. 2-7: The minber

frame of the mihrab is almost identical to that of the entrance portal, except that the painted decorations are different. The mihrab frame is thickly

painted with polychrome floral decorations on plaster recalling floral rumi designs. The floral elements of leaves, tendrils and flowers are densely

intertwined composing medallions painted alternately in white, red, brown and beige. In addition to these colors, which dominate, there are

occasional touches of blue in the medallions. The edge of the mihrab is 20 cm wide and decorated with a string course with floral motifs forming

two types of linked medallions forming a chain. The string course is edged outside and in by a thick red line, as are the medallions. The ground

tone is beige and the medallions are green, blue and grey.

2.3.7. The minber

The minber of the Magribija mosque is made of wood and is 3.70 m long, 0.90 m wide and 6.40

m high. The mimber consists of an entrance portal formed by a wooden frame with a semicircular

wooden plaque above it bearing an inscription from the Qur'an, and a wooden stairway with a railing

consisting of 10-12 steps with a landing at the top known as the kjurs. The kjurs is covered by a conical

canopy on a wooden frame with a finial on top. On either side of the mimber steps is a high wooden

railing simply decorated with a single rhomboidal geometric shape. The lateral triangular areas below the

steps and rail are enclosed and decorated with a single large equilateral triangle with an edging of brown

beading and painted white inside. Below the triangle is a decoration of five small pointed arches. The

mimber is painted with oil paint, predominantly beige, but with touches of brown, green, grey and white.

2.3.8. The ćurs

The ćurs is in the angle to the left of the mihrab on a raised floor. It is made of wood. To the right

of the entrance to the mosque is a small mosque courtyard that is walled off, the barrier extending to the

wooden partition of the portico. This barrier consists of masonry to half its height with the other half

made of iron.



2.4. LEGAL STATUS TO DATE

Pursuant to the law, and by Ruling of the National Institute for the Protection of Cultural Monuments and Natural Rarities of NR Bosnia and

Herzegovina in Sarajevo no. 675/50 of 1950, the Magribija mosque in Sarajevo was placed under state protection.

Pursuant to the law, and by Ruling of the Institute for the Protection of Cultural Monuments and Natural Rarities of NR Bosnia and

Herzegovina in Sarajevo no. 02-635-3 of 1962, the Magribija mosque in Magribija street in Sarajevo was entered on the register of immovable

cultural monuments.

The Regional Plan for the Republic of Bosnia and Herzegovina to 2002 lists the Magribija mosque as a Category I monument.

The Magribija mosque in Sarajevo is on the Provisional List of National Monuments of the Commission to Preserve National Monuments

under serial no. 531.

2.5. RESEARCH AND CONSERVATION AND RESTORATION WORKS

According to information from the Cantonal Institute for the Protection of the Cultural, Historical and Natural Heritage of Sarajevo, between

1971 and 1984 research and conservation works were carried out on the painted decor of the Magribija mosque under the auspices of the mosque

committee and the Institute for the Protection of Monuments of BiH, and the painter Jusuf Začinović. At that time the first coat of paint on the

exterior of the portal and the mihrab was discovered.

The main design project for the reconstruction of the minaret of the Magribija mosque was drawn up in 1997 by Said Jamaković of the

design company Arch design Sarajevo.

The reconstruction of the minaret was carried out from March to December 2000 under the auspices of the Cantonal Institute for the

Protection of the Cultural, Historical and Natural Heritage of Sarajevo, by Kara drvo Kiseljak. It was funded by UNESCO.

The attestation of the stone was carried out by the Institute IMK Sarajevo. The walls of the minaret were reconstructed using tufa from

Fojnica, where the tufa was most suitable in color and mechanical characteristics for this reconstruction. The spiral staircase was rebuilt using the

old surviving steps, with missing steps made of the same hreša stone from a quarry in Sarajevo. The blocks were joined by lead cramps and lime

mortar as was the case when the mosque was first built.



The lower, four-sided pedestal and the prismatic section above it to the height of the mosque steeple had not been destroyed, but were

simply conserved and the rest of the minaret above them was rebuilt. During construction, an analysis of the structural assessment conducted by

Prof. Dr. M. Zlatar revealed that there were high stretching tensions in the lower third of the minaret. Carbon fibre tape technology was used to

provide additional reinforcement in a band 8 m above the prismatic section of the minaret. This was applied by ŢGP Company. After applying the

carbon fibre tape, a thin masking of strips of tufa was added. The project was completed by wiring for electricity and installing a lightning conductor

(Cantonal Institute for the Protection of the Cultural, Historical and Natural Heritage of Sarajevo, web site).

In August 2004 the Cantonal Institute for the Protection of the Cultural, Historical and Natural Heritage of Sarajevo drew up a main design

project for the repair, reconstruction and restoration of the roof and sofas of the Magribija mosque, Stage I.

The project will consist of four stages; as of now the project documentation has been drawn up for Stage I and is with the Federal Ministry

of Regional Planning and Environment for approval. The Commission has received a copy for inspection.

Stage I consist of:

1. Repair and reconstruction of the roof structure and roof cladding

2. Repair of the ceiling joists (including repairs to the barrel vault)

3. Repair, reconstruction and restoration of the exterior sofas

4. Installing under floor heating

Stage II consists of:

1. Reconstruction of the sofa railing

2. Reconstruction of the sofa floor

3. Reconstruction and restoration of interior woodwork

4. Repair and painting interior walls and woodwork

5. Repair, reconstruction and restoration of the mahfil

6. Repair of exterior south-east wall (mihrab wall)

7. Repair and painting facades and exterior woodwork

Stage III consists of:

1. Reconstruction and restoration of decoration on the barrel vault

2. Reconstruction and restoration of the painted decoration of the mahfil

3. Reconstruction and restoration of the painted decoration of the mihrab

4. Reconstruction and restoration of the painted decoration of the portal

5. Reconstruction of the paintings on the interior walls



Stage IV consists of:

1. Remaining installation works

2. Installing floodlighting

3. Making good the exterior of the building (including repairing the harem wall)

According to the project documentation, Stage I provides for the complete replacement of the existing timber roof structure and ceiling

joists, which are in a seriously dilapidated state. The new roof structure is made of Grade I cut fir and spruce wood. The roof cladding of hollow

tiles is also entirely new.

The decision will be made on site, when the plastic sheeting is removed from the ceiling, whether the panelled ceiling and painted

decoration can be retained (with restoration work) or whether the decorations must be photographed and reconstructed on a new ceiling.

Restoration works on the sofas will take place in line with the existing state of the structure. The pillars with their stone bases and capitals

are being retained, since the oak wood of which they are made is in good condition they need cleaning and treating with a protective application of

linseed oil. The stone is also being cleaned and repaired where necessary.

2.6. CURRENT CONDITION OF THE MOSQUE

An on-site inspection conducted in December 2004 ascertained as follows:

There is visible physical damage to the building on the facades and portico

The stone bases of the pillars are broken, there are numerous cracks in the wooden pillars and beams, and the floor of the sofas is in very

poor condition

Stains caused by damp penetration are to be observed on the plaster in the upper reaches of the mosque, particular in the mahfil area of

the north-west wall by the staircase to the mahfil

There are particularly noticeable cracks in the plaster in the interior of the mosque in the upper reaches. These cracks are also visible on

the exterior facade, though here they are smaller

Other than the minaret and part of the roof, which have been repaired in part following war damage, the mosque building is in poor

condition

The area most at risk is the barrel vault which has collapsed due to leakage of rainwater, particularly the decoration. The ceiling is now

covered with plastic sheeting

The decoration on the outer portal is damaged almost all over, with only faded fragments remaining.

3 STRUCTURAL ANALYSIS


Fig. 3-2:

Longitudinal section of the minaret

Fig. 3-1: Facade of the minaret

Fig. 3-3: Cross section of the base Fig. 3-4: Cross section of the šerefe

3.1. GEOMETRICAL AND MATERIAL PROPERTIES OF THE MINARET

Material E [kN/m2] G [kN/m

2] γ [kN/m

3] µ

Hreša ; Sedra 5×106 6×105 28,0 0,1

2,26m 3,21m

5,7m

1,5m

15,3m

5,5m

Chapter – 3 Structural Analysis


Fig. 3-5:

3D model – shell elements Fig. 3-7:

Modal Analysis – first three modes

T1 = 0,40147sec T2 = 0,40147sec T3 = 0,07267sec

Fig. 3-6: Response Spectrum

3.2. NUMERICAL 3D MODEL

3.2.1. Modal Analysis

During calculations, SAP 2000 V.15.1.0 was used.

Chapter – 3 Structural Analysis


Fig. 3-8:

Internal forces

Fig. 3-9:

Internal forces at connection between pedestal and minaret

Fig. 3-10: Maximum top movement without FRP

Fig. 3-11:

Maximum top movement with FRP

3.2.2. Seismic Analysis

U = 0.12423m

U = 0.07512m

4 CONCLUSION


Fig. 4-1: The minaret reinforced with FRP

Analysis shown that with reinforcing the parts of the minaret which are the most vulnerable (pedestal and connection between pedestal and

minaret), there is enough safety because of stability of the minaret in case of design value of seismic demand (10% in period of 50 years – strong

earthquake)

3D analysis provides evaluation of the minaret behaviour under seismic forces, what include determininig possible cracking zones and

types of cracking. Additional research should be provided about determining design response spectrum specially adjusted for this kind of

structures. More realistic values of R – factor (design factor for seismic load) and damping coefficient should

be researched by experimental and analytic methodes.

On other hand, full connection between masonry structer and FRP layers must be provided. Problem

could be solved with usage of anchorage or by the connection between longitudinal FRP lanes and

foundation of the minaret. The FRP lanes rounded around masonry structure can cause moisture because of

unpermeability of the FRP layers, what is bad effect.

Low fire resistance of the FRP lanes could be improved by adding a thin protective layer of concrete

or plaster which will hide FRP lanes in same time. Results of numerical analysis show that the biggest

demages appear in base zone and in lower part of minaret, so application of FRP lanes around critical

regions will improve laterally behaviour of the structure.

LITERATURE


1911. Jnl of the National Museum in Sarajevo, XXII, Kemura, Sejfudin, XLVII. Šejh Magribina džamija u Magribiji, (The Shaikh Magriba

mosque in Magribija) 1911.

1980. Institute for Architecture, Town Planning and Regional Planning of the Faculty of Architecture in Sarajevo, Regional plan for Bosnia

and Herzegovina, Stage «B» - valorization of natural, cultural and historical values, Sarajevo, 1980.

1997. Main design project for the reconstruction of the minaret of the Magribija mosque, Arch design Sarajevo, designer Jamaković Said,

March 1997.

1998. Mujezinović, Mehmed, Islamska epigrafika Bosne i Hercegovine, (Islamic Epigraphics of BiH) bk. I, Sarajevo Publishing, Sarajevo,

1998.

2004. Cantonal Institute for the Protection of the Cultural, Historical and Natural Heritage of Sarajevo, Main design project for the repair,

reconstruction and restoration of the roof and sofas of the Magribija mosque – Stage I .

seismic analysis of the minaret

Documents